Narrowband laser apparatus and spectral linewidth measuring apparatus

Abstract

A narrowband laser apparatus may be provided with a laser resonator including optical elements for narrowing a spectral linewidth, a spectrometer configured to detect spectral intensity distributions of multiple pulses included in a pulsed laser beam output from the laser resonator, a spectral waveform producer configured to produce a spectral waveform by adding up the spectral intensity distributions of the multiple pulses, a device function storage configured to store a device function of the spectrometer, a wavelength frequency function generator configured to generate a wavelength frequency function which represents a frequency distribution of center wavelengths of the multiple pulses, and a deconvolution processor configured to perform deconvolution processing on the spectral waveform with the device function and the wavelength frequency function.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation application of International Application No. PCT / JP 2015 / 084621 filed on Dec. 10, 2015. The content of the application is incorporated herein by reference in its entirety.BACKGROUND1. Technical Field[0002]The present disclosure relates to a narrowband laser apparatus and a spectral linewidth measuring apparatus.2. Related Art[0003]With miniaturization and high integration of a semiconductor integrated circuit, improvement of resolution is demanded in a semiconductor exposure apparatus (hereinafter, referred to as “exposure apparatus”). Accordingly, the wavelength of light emitted from a light source for exposure is being shortened. As the light source for exposure, a gas laser apparatus is used in place of an existing mercury lamp. As the gas laser apparatus for exposure, a KrF excimer laser apparatus that emits ultraviolet rays of a wavelength of 248 nm and an ArF excimer laser apparatus that emits ultr...

AI Technical Summary

Benefits of technology

The present patent text describes a narrowband laser apparatus and a spectral linewidth measuring apparatus that can produce a spectral waveform by adding up the spectral intensity distributions of multiple pulses in a pulsed laser beam output from a laser resonator. The apparatus includes a spectrometer, a device function storage, a wavelength frequency function generator, and a deconvolution processor. The apparatus can measure the linewidth of a spectral line with high accuracy. The technical effects of this apparatus include the ability to produce high-quality spectral waveforms and accurately measure the linewidth of a spectral line.

Problems solved by technology

Therefore, it is necessary to narrow the spectral linewidth of the laser beam emitted from the gas laser apparatus such that the color aberration becomes ignorable.

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